octeontx2-pf: Simplify the receive buffer size calculation

This patch separates the logic of configuring hardware
maximum transmit frame size and receive frame size.
This simplifies the logic to calculate receive buffer
size and using cqe descriptor of different size.
Also additional size of skb_shared_info structure is
allocated for each receive buffer pointer given to
hardware which is not necessary. Hence change the
size calculation to remove the size of
skb_shared_info. Add a check for array out of
bounds while adding fragments to the network stack.

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
index 2d2b67319340..0cc6353254bf 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_txrx.c
@@ -181,8 +181,9 @@ static void otx2_set_rxtstamp(struct otx2_nic *pfvf,
 	skb_hwtstamps(skb)->hwtstamp = ns_to_ktime(tsns);
 }
 
-static void otx2_skb_add_frag(struct otx2_nic *pfvf, struct sk_buff *skb,
-			      u64 iova, int len, struct nix_rx_parse_s *parse)
+static bool otx2_skb_add_frag(struct otx2_nic *pfvf, struct sk_buff *skb,
+			      u64 iova, int len, struct nix_rx_parse_s *parse,
+			      int qidx)
 {
 	struct page *page;
 	int off = 0;
@@ -203,11 +204,22 @@ static void otx2_skb_add_frag(struct otx2_nic *pfvf, struct sk_buff *skb,
 	}
 
 	page = virt_to_page(va);
-	skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
-			va - page_address(page) + off, len - off, pfvf->rbsize);
+	if (likely(skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)) {
+		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+				va - page_address(page) + off,
+				len - off, pfvf->rbsize);
+
+		otx2_dma_unmap_page(pfvf, iova - OTX2_HEAD_ROOM,
+				    pfvf->rbsize, DMA_FROM_DEVICE);
+		return true;
+	}
 
-	otx2_dma_unmap_page(pfvf, iova - OTX2_HEAD_ROOM,
-			    pfvf->rbsize, DMA_FROM_DEVICE);
+	/* If more than MAX_SKB_FRAGS fragments are received then
+	 * give back those buffer pointers to hardware for reuse.
+	 */
+	pfvf->hw_ops->aura_freeptr(pfvf, qidx, iova & ~0x07ULL);
+
+	return false;
 }
 
 static void otx2_set_rxhash(struct otx2_nic *pfvf,
@@ -349,9 +361,9 @@ static void otx2_rcv_pkt_handler(struct otx2_nic *pfvf,
 		seg_addr = &sg->seg_addr;
 		seg_size = (void *)sg;
 		for (seg = 0; seg < sg->segs; seg++, seg_addr++) {
-			otx2_skb_add_frag(pfvf, skb, *seg_addr, seg_size[seg],
-					  parse);
-			cq->pool_ptrs++;
+			if (otx2_skb_add_frag(pfvf, skb, *seg_addr,
+					      seg_size[seg], parse, cq->cq_idx))
+				cq->pool_ptrs++;
 		}
 		start += sizeof(*sg);
 	}